Control system for discharging concrete grout to form piles



H. L. MOOR June 14, 1966 CONTROL SYSTEM FOR DISGHARGING CONCRETE GROUT TO FORM FILE-.5

Filed May 1, 1961 4 Sheets-Sheet 1 SUMP HYDRAULIC 8 PUMP r MOTOR INVENTOR. HERMAN l MOOR @M RNEY June 14, 1966 H. L. MOOR 3,255,592

CONTROL SYSTEM FOR DISCHARGING CONCRETE GROUT TO FORM PILES Filed May 1, 1961 4 Sheets-Sheet 2 52 33 75 W? 72 I I L Z7 52 2Q 1,-

INVENTOR. HERMAN L. MOOR ATTORNEY June 14, 1966 H. L. MOOR 3,

CONTROL SYSTEM FOR DISCHARGING CONCRETE GROUT TO FORM FILES Filed May 1, 1961 4 Sheets-Sheet 5 ACGUM. p) 4 INVENTOR. HERMAN L. MOOR ATTORNEY 4 Sheets-Sheet 4 /07 m; w /0/ 7 i H. L. MCDOR R mm m T M m T m M m Ha m w M W 5 CONTROL SYSTEM FOR DISCHARGING CONCRETE GROUT TO FORM PILES Filed May 1, 1961 June 14, 1966 3,255,592 CONTROL SYSTEM FQR DISCHARGING CON- CRETE GROUT T FORM PILES Herman L. Moor, 461 S. La Salle St, Chicago, Ill. Filed May 1, 1%1, Ser. No. 127,761 9 Claims. (Cl. 61-5364) This invention relates to a control system for coordinating simultaneous operations, and one embodiment relates to means for coordinating the rate of feed of a fluent material and the rate of movement of a member discharging such material within a space receiving said material.

This invention finds particular utility in the construction of concrete foundation piles, such as uncased pressurized cast-in-place concrete foundation piles. The construction of uncased pressurized cast-in-place concrete foundation piles involves boring a hole in earth to the required depth by the use of a drill or auger having a hollow stem and then pumping concrete grout down said stem and simultaneously elevating the anger at a rate coordinated to produce a continuous pile in the bore or cavity formed by the withdrawal of the auger.

The regulation and control of the rate at which concrete grout is poured or supplied and the rate at which the anger is hoisted or elevated has been difficult heretofore because the bottom end of the auger and the foundation pile being formed are below ground surface and cannot be observed as the pile is being formed. If the auger is raised without simultaneously introducing a volume of concrete grout equivalent to the volume of the cavity or void created by elevating the auger, earth may cave into the cavity or void and thereby interrupt the continuity of the concrete pile, rendering it defective. The defective character of a foundation pile may not be detected until failure occurs after a building load is applied to the pile.

It is desirable to coordinate the rate of flow or supply of concrete grout to the rate at which the auger is withdrawn in such a manner that the volume of concrete grout being supplied is equal to or greater than the volume of the auger and entrained earth that is displaced as the auger is raised, and it is the primary object of this invention to provide a system for effecting such control.

A further object is to provide a system wherein the relationship between two variables of a system is indicated or recorded in terms of pressure variations and means are provided for regulating or modulating said variables to establish and maintain a desired relationship therebetween.

A further object is to provide a control system of this character wherein the pressure of concrete grout discharged at or near the tip of an auger is measured and is transmitted to coordinating means in opposition to a counterbalancing or regulating pressure acting on said coordinating means and manually or automatically con trolled, so as to actuate said coordinating means in such a manner as to control the relationship between the operation of hoisting mechanism for the auger and concrete grout supply mechanism connected to the auger.

A further object is to provide a control system of this character having power operated means for controlling the rate and pressure at which concrete grout is supplied to the hollow stern of an auger and power operated means for hoisting the auger, which are so controlled with relation to each other as to maintain a desired relationship by proportioning means responsive to means sensing fluctuations of pressure at grout discharge point relative to a regulated pressure.

Other objects will be apparent from the following specification.

Patented June 14, 1966 In the drawings:

FIG. 1 is a View of the system with parts shown schematically and illustrating a coordinating device in cross-section in one position;

FIG. 2 is a sectional view of the coordinating device illustrated in FIG. I adjusted to a different operative condition;

FIG. 3 is a view of the coordinating device shown in FIG. 1 in a third operative'position;

FIG. 4 is a fragmentary schematic view illustrating a reversing valve employed in the system in FIG. 1 in a different operative position than that shown in FIG. 1;

FIG. 5 is another view similar to FIG. 4 but illustrating a still different operative position of the reversing valve;

FIG. 6 is a schematic view of a modified embodiment of the system, with parts shown in section;

FIG. 7 is a schematic View of still another modified embodiment of the invention, with parts shown in section;

FIG. 8 is a schematic view of still another modified embodiment of the invention.

Referring to the drawings, and particularly to FIGS. 1 to 5 thereof which illustrate one embodiment of the invention applied to means for producing a cast-in-place concrete foundation pile, the numeral 10 designates the elongated tubular stem of an earth auger having helical flights 11 and a leading tip 12. The helical flights 11 terminate spaced above the free end of the tip 12, and thetubular'stem of the auger has an aperture 13 adjacent the tip 12 through which concrete grout may be discharged adjacent the leading end of the auger. A small tube 14 extends through the auger stem 10 with clearance to terminate adjacent the outlet 13 for purposes to be described. The auger is preferably of the construction and is preferably used in substantially the manner illustrated and described in my co-pending patent application for method and means for making concrete piles, Ser. No. 76,030, filed December 15, 1960. Any,

suitable means 15, preferably power operated, may be provided for the purpose of rotating and advancing the auger to drill a hole in the earth to a selected depth with minimum displacement of the earth so that earth is retained between the adjacent flights of the auger and above the uppermost flight in the manner illustrated in FIG. 1.

At its upper end the tubular stem 10 of the anger is connected to a mud swivel or swivel coupling 16 which in turn is connected by means of a conduit 17 with a pump 18 into which concrete grout is fed from a supply 19, such as a hopper. The pump 18 is preferably of the type actuated by a hydraulic motor, the part 18 as here schematically shown illustrating both the hydraulic motor and the pump.

The mud swivel or coupling 16 is provided with suspension means 21 to which is connected the end of a cable 22 trained around a sheave or hoist drum 23 actuated by a reversible power member 24 which is preferably a hydraulic motor.

A coordinating or proportioning control element, here shown as a hydraulic valve 26, has a body provided with a bore therethrough and a plurality of internal circumferential grooves. In the form shown, the valve body has a center groove 27 with which a valve inlet 28 communicates, a groove 29 with which an outlet 30 communicates and a groove 31 with which an outlet 32 communicates. Supplemental grooves 33 are formed adjacent the opposite ends of the housing 26, each having a drain opening 34.

A valve spool 35 is shiftable endwise and fits snugly in the bore of the valve casing 26. Spool 35 is characterized by a center circumferential land 36 of an axial dimension less than the axial dimension of the groove 27 and circumferential end lands 37 and 38 of axial dimension greater than the axial dimensions of the grooves 33. The portions of the spool 35 between said lands 36, 37 and 38 are of a diameter less than the diameter of the bore of the valve housing. Center land 36 is spaced substantially equally from the respective end lands 37 and 38 of the valve spool at distances greater than the combined width of one of the grooves 29 or 31 and the portion of the bore separating said groove from the cen ter groove 27 of the valve casing.

A sump 40 containing a supply of oil or other liquid under pressure has associated therewith a pump 41 for pumping liquid from the sump 40 into and through a supply line or conduit 42 leading to the valve inlet 28. A pressure modulating valve 43 is located in the line 42 at a convenient position. A line or conduit 44 communicates with the outlet 30 of the valve housing groove 29 and leads to one port of a manually operable reversing valve 45. A conduit 46 connects one port of the reversing valve 45 with the reversible hydraulic power member or motor 24 and a conduit 47 connects another port of the reversing valve 45 with the reversible power mem her or motor 24. A discharge line or conduit 48 communicates with still another port of the reversible valve 45 and extends to the sump 40.

A conduit 49 communicates with the outlet 32 of the valve housing groove 31 and with the hydraulic motor of the pump unit 18. A conduit 50 communicates with the hydraulic motor 18 and with the return conduit 48.

A drain conduit 51 branches from the return conduit 48 and has branches 52 thereof communicating with the valve outlet ports 34 in communication with the drain grooves 33 of the valve housing 26.

Means are provided for adjusting the setting of the valve 26 and thereby coordinating or modulating the simultaneously operating variables, such as the grout pump motor 18 and the hoist motor 24, which means utilize means for sensing and measuring the pressure condition existing at or adjacent the grout outlet 13 in the auger stem 10. The adjusting means, as illustrated in FIG. 1, are preferably pneumatic and include an air compressor 60 or other meansfor supplying air under pressure to a line or conduit 61 leading to the mud swivel or grout coupling 16 and to the conduit 14 within the auger stem 10. The line 61 may have interposed therein an accumulator 62, if desired, and preferably has interposed therein at spaced points the regulating valves 63 and 64. A pressure gauge 65' is preferably connected in line 61 between the mud swivel 16 and the valve 65.- A branch line 66 communicates with line 61 between the mud swivel 16 and the valve 64 and supplies air under pressure to any suitable pressure responsive member. As here shown, the pressure responsive member comprises a cylinder 67 mounted upon or otherwise juxtaposed in predetermined relation to one end of the valve housing 26. Cylinder 67 houses a piston 68 having a plunger 69 projecting therefrom and substantially coaxial with and bearing against the adjacent end of the valve spool 35.

A compressed air line on conduit 71 connected with a source of compressed air, as by branching from the line 61 at a point between the valves 63 and 64, communicates with a suitable second pressure responsive member mounted or otherwise fixedly oriented to the end of the valve housing 26 opposite that with which the cylinder 67 is associated. As here shown, the second pressure responsive member is a cylinder 72. The pressure responsive members or cylinders 67 and 72 are preferably similar, i.e., are preferably of the same diameter or bore. A piston 73 is mounted in cylinder 72 and has a plunger 74 projecting therefrom coaxially of and engageable with the adjacent free end of the valve spool 35.- It will be apparent, therefore, that the positions of the plungers 69 and 74 will determine the position of the valve spool 35 in the coordinating valve 26.

A modulating valve 75 is interposed in line 71, and pressure gauges 76 and 77 are connected in line 71 at opposite sides of modulating valve 75. Valve 75 has an actuating lever 78.

The system is illustrated in FIG. 1 with the coordinating valve 26 in a position to permit the supply of hydraulic fluid from line 42 to be diverted substantially equally to the valve housing grooves 29 and 31 and to be supplied thence in substantially equal volume or rate of flow through lines 44 and 49 to the hydraulic hoist motor 24 and to the grout feed hydraulic motor and pump 18 respectively. Thus, in the setting of the system illustrated in FIG. 1, grout is fed from the grout supply 19 by the pump 18 through the conduit 17 and coupling 16 to the tubular stem 10 of the auger from which it is discharged at the lower end of the anger at outlet 13 into the cavity in the earth below the auger flights. At the same time the hydraulic hoist motor 24 is operated to rotate the sheave or pulley 23 in a direction to raise or elevate the auger. It will be understood that during such operation of the hoist motor 24 and the sheave or hoist drum 23 the mechanism 15 will be disengaged or free so that the raising or elevation of the auger will occur substantially without rotation and in a manner to lift therewith the earth between the flights of the auger and the earth surrounding the portion of the auger stern above the uppermost flight of the auger, as explained in my co-pending application, Ser. No. 76,030, filed December 15, 1960. It will be understood that this hydraulic operation of the grout pump 18 and the hoist motor 24 will occur in cases where the pump 41 is operating and the modulating or control valve 43 is open to permit the flow of hydraulic fluid in the system to and through the coordinating valve 26, the grout pump 18 and the hoist motor 24.

Assuming that the valves 63 and 64 to the air line 61 are closed, air will be prevented from flowing in the line 61 from the compressor 60 and the accumulator 62. Any air pressure existing in the line 71 may be maintained therein by the modulating valve or pressure regulator 75. Any desired pressure can be maintained in the portion of the line 71 between the modulating valve or pressure regulator 75 and the cylinder 72 as long as an equal or greater air pressure is maintained in the portion of the air line 71 between the line 61 and the modulating valve or pressure regulator 75. For purposes of illustration, it may be assumed that the actuating lever 78 of the modulating valve 75 will close or substantially close the modulating valve 75 at one position, such as the full line position shown in FIG. 1, and will open or substantially open valve 75 at a second operative position, such as the dotted line position shown in FIG. 1. The extent of opening of the modulating valve 75 will vary with variations in the positioning of the lever 78 between the two extremes. The relative pressures on opposite sides of the modulating valve 75 can be readily observed by an operator viewing the pressure gauges 76 and 77.

The device is conditioned for operation, assuming that the supply of air under pressure is operative, by opening the valve 63 to develop in the line 71 any selected pressure as measured by gauge 76. Then, if valve 64 is opened slightly, air will flow through line 61 to the mud swivel or coupling 16, the conduit 14 within the auger stem 10 and will escape from the auger stem through the grout discharge hole 13 near the tip of the auger. Since the grout discharge hole 13 may be covered or submerged in earth, concrete grout or water, valve 64 is adjusted to increase air pressure in the line 61 and the conduit 14 until it becomes suificient to force discharge at the hole 13 and establish pressure equilibrium in lines 61 and 14. The pressure existing in the line and the fluctuations thereof are indicated by gauge 65 and must exceed the pressure of the concrete grout supply.

Inasmuch as pressure responsive member 67 is in communication with line 61, the pressure in that member acting therein, as upon the piston 68, is the pressure in the line 61 and acts to urge the piston 68 coaxially of and toward the valve spool 35 in a manner to urge spool 35 endwise toward the right as viewed in FIG. 1. The opposite end of the valve spool 35 bears against the plunger 74 of the opposed pressure responsive member, such as the plunger of the piston 73 in the cylinder 72, and hence any movement of the valve spool 35 to the right will similarly move the plunger 74 and the piston 73 to the right, which action must occur against the air pressure in the line 71. Whenever this condition exists, namely, a movement of the valve spool 35 to the right as seen in FIG. 1 as a result of a pressure condition acting on pressure responsive member 67 in excess of that acting upon pressure responsive member 72, the condition can be observed by reading the two gauges 76 and 77.

When the operator observes that pressure indicated on gauge 76 exceeds that indicated on gauge 77, the valve lever 78 may be moved slightly to adjust the modulating valve 75 in a direction to increase the air pressure in the line 71 between valve 75 and cylinder 72. The modulating valve 75 can be actuated to introduce in the pressure responsive member 72 an air pressure exceeding that within the pressure responsive member 67 whenever air can escape from the grout opening 13 of the drill stem. As soon as the pressure in pressure responsive member 72 exceeds that in member 67, the spool 35 of the coordinating valve 26 will be moved toward the left. 7

FIG. 2 illustrates an adjustment of the coordinating valve 26 in a case in which the pressure in member 67 exceeds that in member 72. The setting in this instance is shown such as to locate the-center land 36 of the valve spool adjacent to the internal circumferential rib in the valve housing between the grooves 27 and 31. This permits free flow of hydraulic fluid from the valve inlet 28 to the outlet port 30 with which is connected the line 44 leading to the hydraulic hoist motor 24. In the FIG. 2 setting, the flow of liquid from the inlet 28 of the coordinating valve to the outlet 32 of said valve which communicates with the groove 31 and with the line 49 leading to the pump motor 18 for pumping concrete grout is materially restricted.

FIG. 3 shows a reverse position resulting from an increase in pressure in member 72 as compared to that in member 67 sufiicient to position the center land 36 of the valve spool 35 within the bore of the valve casing between the center groove 27 and the groove 29. This diverts substantially all flow ofoil from the inlet 28 of the coordinating valve to the outlet port 32 which is connected to the grout motor pump 18 by the line 49.

Any oil leakage which may occur in any setting of the valve around the lands 37 and 38 of the spool extends only to the end grooves 33 from which it may drain through the openings or ports 34 into the drain return conduits 51, 52 communicating with the return line 48 extending to the sump 40.

The reversing valve 45 is preferably manually controlled and has three' different positions. The position of the valve shown in FIG. 1 has been assumed to be the position required for operation of the hoisting motor 24 in a direction to raise the auger 10. The position illustrated in- FIG. 4 is a closed position which shuts oil flow of liquid from the coordinating valve 26 to the hoist motor 24. The position illustrated in FIG. 5 accommodates a reversal of the fiow path to and through the reversing valve 45, the conduits 46 and 47, and the reversible hydraulic hoist motor 24 so as to produce a direction of motor operation opposite that provided by the FIG. 1 setting.

In the operation of forming a concrete uncased pressurized cast-in-place pile or foundation as here illustrated, assuming that the drilling operation by the auger has proceeded to the desired depth and that both the oil pressure supply means and air pressure supply means are operative, the valve 63 will be opened and valve 64 will be partly opened after the reversing valve 45 has been set in the position shown in FIG. 1 and before the oil pressure modulating valve 43 is opened. The lever 78 of the pressure modulator 75 may first be operated at the extreme right position to fully open the same, and at the same time the oil supply valve 45 will be opened. The operation of the modulating valve 75 will be such as to supply air under pressure to the pressure responsive member member 72 in excess of the pressure of the air in the pressure responsive member 67 to thereby cause the valve spool 35 to assume the setting illustrated in FIG. 3. The FIG. 3 setting of the coordinating valve 26 results in the direction of all oil flow through that valve to and through the grout feed pump motor 18.

The supply of grout through the line 17 and the mud swivel 16 to the auger stem 10 causes grout to be discharged at the opening 13 into the hole in the earth below the auger to be confined below the auger. The grout pressure may cause displacement of the earth around the auger tip while in its lowermost position and below the position shown in FIG. 1 to create an enlarged pile tip or bulb 79. As the volume in the pile tip 79 increases, the grout injection pressure will also increase. This increase in grout pressure reduces discharge of air at the end of the air line 14 near the grout discharge 13, and a corresponding increase in air pressure in lines 14 and 61 occurs. In effect the grout pressure at the discharge aperture 13 of the auger stem is sensed and indicated on gauge 65 and issimultaneously transmitted to the pressure responsive member 67. When the desired volume of grout has been injected into the pile tip 79, or when desired grout injection pressure has been reached as read on gauge 65, the lever 78 on the pressure modulator 75 may be operated to reduce the air pressure in line 71 as shown on the gauge 77. This changes the relative forces applied by members 67 and 72 and to the valve spool 35 and in doing so will divide or proportion oil flow from line 42 between line 44 leading to the hydraulic 'hoist motor 24 and line 49 leading to the hydraulic grout feed motor 18. This will automatically raise the auger 10 while continuing grout supply. The valve 75 will preferably be modulated to maintain substantially uniformly decreasing grout pressure beneath the tip of the auger as the auger is raised.

Inasmuch as considerable grout pressure will exist when the tip of the auger is at substantial depth in the earth, but negligible grout pressure will be permissible as the auger tip approaches the surface of the earth, it is necessary to adjust the setting of the modulating valve 75 to compensate for such varying pressure requirements. Thus, as the tip of the auger is elevated, the operator can progressively swing the lever '78 of the modulating valve toward closed position so as to unbalance the setting of the coordinating valve toward a setting as illustrated in FIG. 2, wherein the rate of elevation of the anger is increased while the rate and pressure of grout supply is decreased. In this way, the eruption of grout around the auger near the surface can be avoided without danger of any interruption in the continuity of the pile being formed.

FIG. 6 illustrates a modified embodiment of the invention with parts similar to those illustrated in the embodiment shown in FIG. 1 bearing the same reference numerals employed in FIG. 1. In this embodiment, the hoist drum 23 is driven by a reversible motor orpower member 82 actuated by any suitable source of power and having a control lever or actuator 83 shiftable to control-the direction and rate of operation thereof. The concrete supply or hopper 19 has a pump 84 associated therewith, having a drive means actuated by any suitable power source and controlled by a lever or actuator 85 for the purpose of controlling the rate at which pump 84 discharges concrete grout through the conduit 17.

Hydraulic control member 86 is associated with the actuator 83 of the motor 82 and hydraulic control member 87 is associated'with the controller 85 of the grout pump 84. As here shown, each of the controllers 86 and 87 comprises a cylinder 88 within which is shiftable a piston 89 having a piston rod 90 slidable in an opening in one end of the cylinder and encircled by a coil spring 91 within the cylinder urging the piston 89 toward the opposite end of the cylinder from which the piston rod 90 projects. A connecting rod 92 connects the controller 86 with the motor actuator 83 and a connecting rod 93 connects the controller 87 with the actuator 85 of the pump 84.

The line 44 connects the discharge port 30 of the coordinating valve 26 with an inlet port 94 in the cylinder '88 of the controller 86 at the end of said cylinder opposite that from which the piston rod 90 projects, and line 48 is connected to an outlet port 95 of the cylinder of the controller 86 positioned adjacent the inlet 94, and at the same end of the cylinder. The line 48 extends to the sump 40 and has a regulating valve 96 interposed therein.

The line 49 which communicates with the outlet port 32 of the coordinating valve 26 is connected to an inlet port 97 in the cylinder of the controller 87 located at the end thereof opposite that from which the piston rod 90 projects. At the same end of the cylinder of the controller 87 is located an outlet port 98 at which the conduit 50 leading to the discharge conduit 48 is connected. A regulating valve 99 is interposed in the lead or conduit 50.

The operation of this embodiment of the invention is substantially the same as that in FIG. 1 with the exception that the hydraulic fluid in the system controlled by the coordinating valve 26 operates merely to control the setting of controllers 86 and 87 associated with the reversible hoist motor 82 and the concrete grout pump 84. In the operation of this system the regulating valves 96 and 99 are set to control the venting of controllers 86 and 87 to determine the rate at which oil can flow through the line 48 from the outlet of the controller 86 and through the line 50 from the outlet 98 of the controller 87. The setting of the regulating valves 96 and 99, together with the setting of the valve 43, is required to place the system in condition for operation. Normally, this setting may be assumed to be such as to supply an adequate flow of oil for actuation of the controllers 86, 87, and a setting of the valves 96 and 99 to permit substantially the same rate of flow through both lines 48 and 50 at a time when the coordinating valve 26 is set to discharge substantially equal volumes of oil through the lines 44 and 49.

In the operation of the system, whenever the coordinating valve 26 is shifted in a manner to unbalance the flow of oil in the lines 44 and 49, an increase of flow will occur to one of the two controllers 86 and 87 and a decrease in flow will occur to the other controller. The controller at which increased flow is experienced will have the piston 89 thereof shifted against the action of the spring 88 by reason of the fact that the increased volume or rate of flow cannot be accommodated through the out let because of the restricted setting of the valve associated therewith, that is, one of the valves 96 and 99. At the same time, the cylinder at which reduced rate of supply occurs will have the piston 89 shifted by its spring by reason of the fact that its associated restricting valve, i.e., the other of the valves 96 and 99 remains in a constant setting will permit oil to escape faster than it enters the supply line to said cylinder. Thus it will be apparent that by connecting the controllers 86 and 87 through the connecting rods 92 and 93 to members 83 and 85, which may constitute throttles, clutches or speed controllers for engines or motors driving the hoist and the pump, the relative speeds of the hoist and the pump are regulated as desired. Also, it will be seen that this system can be used in cases where the hoist and the pump are driven by separate engines or motors and are remote from each other. One advantage of this embodiment or system is that the size and pressure of the hydraulic system used in eflfecting control can be greatly reduced compared to s that illustrated in FIG. 1 because of the reduction in the force required to be exerted in the operation of this embodiment of the invention.

FIG. 7 illustrates a modified embodiment of the invention wherein parts similar to those used in preceding embodiments bear the same reference numerals. In this construction the coordinating valve 100 is an air valve having a cylinder 101 with a bore therethrough for slidably receiving a valve spool 102 which is positioned in the valve housing by the plunger 69 of the pressure responsive member 67 and by the plunger 74 .of the pressure responsive member 72. The valve spool 102 has spaced circumferential grooves defining a central circumferential land 103 and end lands 104 slidable in the bore of the valve housing 101. A central internal circumferential groove 105 in the valve housing 101 communicates with an inlet port 106. A pair of longitudinally spaced circumferential grooves 107 and 108 in the valve housing 101 on opposite sides of. groove 105 communicate respectively with outlets 109 and 110. A pair of sealing O-rings are seated in circumferential grooves between the opposite ends of the valve housing 101 and the grooves 107 and 108, respectively, to seal the housing against leakage of air at the end of the bore thereof.

A line 111 leads from a source of compressed air, such as the accumulator 62, to the inlet port 106 of the coordinating valve 100, and has a regulating valve 112 interposed therein. A line 113 is connected with valve outlet 109 and with an inlet port at the end of a controller, such as cylinder 114. Cylinder 114 has a piston 115 therein and a piston rod 116 projecting therefrom at the end opposite the air inlet. Coil spring 117 encircles the piston rod 116 to urge the piston 115 in the direction of the air inlet port. Connecting rod 118 connects the end of the piston rod 116 with the actuator 83 of the reversible motor 82 which actuates the hoist drum 23. A line 119 branches from line 113 and has a bleed valve 120 connected therein for regulating the rate of bleed of air therethrough to atmosphere.

A line 121 is connected with the outlet 110 of the valve 100 and with one end of a controller, such as a cylinder 122 having slidable therein a piston 123 provided with a piston rod 124 slidably projecting from the end of the cylinder 122 opposite the end at which air is supplied by line 121. A coil spring 125 encircles the piston rod 124 and urges the piston 123 toward the air supply inlet. A connecting rod 126 is connected to the piston rod 124 and to the actuator 85 for controlling the motor which actuates the pump 84 for supplying grout from hopper 19 to conduit 17. A line 127 branches from line 121 and has a bleed valve 128 connected therein. All other air connections in the system illustrated in FIG. 7 are similar to those utilized in FIG. 1.

In the operation of this embodiment of the invention, the parts function in the same manner described above with respect to FIG. 1 with the exception that air only is utilized in the system, and the coordinating valve 100 serves to regulate the supply of air and the proportion of air to the controllers 114 and 122 associated with the hoist motor 82 and the grout pump 84, respectively. This device has the same advantage of sensing the pressure condition existing at the point of grout discharge and observance thereof at gauge 65 and of utilization of the regulator 75, 78 to control the position of the valve spool of the coordinating valve 100 in response to a reading of the relationship of pressure conditions acting upon the pressure responsive members 67 and 72 by observing the pressure indicators 65 and 77.

The embodiment of the invention illustrated in FIG. 8 is substantially the same as that illustrated in FIG. .7 in that the coordinating valve 100 serves to regulate the division of compressed air supplied by line 111 between the lines 113 and 122 under the control of the regulator 75, 78 and the pressure responsive members 67, 72, as explained above. In this instance line 113 has a reversing valve 130 interposed therein which serves to control the direction of air flow to a reversible air motor 131 serving to drive or actuate the hoist drum 23. The line 122 is connected to an air motor 132 for driving a pump by means of which grout from grout supply 19 is discharged to the conduit 17. The functioning of this device is similar to that in each of the preceding devices, except as the use of air motors is involved, together with elimination of the need for bleed valves 120 .and'128, such as are illustrated in FIG. 7.

It will be apparent from the foregoing that each embodiment of this invention entails means for sensing the pressure condition existing at a given point as the result of the conjoint reaction of two variable factors, such as rate of grout supply and position of grout discharge. The pressure so sensed is applied to means for positioning a coordinating valve in opposition to a second manually controlable means for positioning the coordinating valve. The coordinating valve acts to proportion controlling forces between the means for controlling the two variables, such as the grout supply pump and the hoist motor, as required by variations in the pressure sensed by the sensing means. Thus, except for initial setting of such valves as 63, 64, 43 and 45 of the system shown in FIG. 3 required to place the device in operation, only modulation of the setting of the pressure regulator valve 75 is necessary to coordinate simultaneously two variable conditions acting to produce a given result, such as the formation of a continuous foundation pile in the example selected for illustration. This example is not intended to be limiting, and it is apparent that the system may be applied to many other instances in which it is necessary to regulate or proportion or modulate two variable conditions,

elements or factors which simultaneously function to produce a desired result.

While the system has been illustrated as serving to control two variables, the control of a greater number of variables can be accomplished by simply using additional coordinating valves at branches dividing from lines, such as 44 and 49, extending from a primary coordinating valve, which branches control branch lines leading to the respective controls for each of the variables. Similarly, it is possible to use the system to control only one variable, such as the normally dominant or most greatly fluctuating variable in a case where the other variable or function operates inherently within predetermined limits.

As an example of the use of the system to control only one variable in the production of an uncased pressurized cast-in-place concrete foundation pile of the type illustrated in FIG. 1, it would be possible to provide grout-pumping means entirely independent of and controlled separately from the control valve 26 by omitting the lines 49 and 50 shown in FIG. 1. In such an instance the device would still function to raise the auger 10 automatically. Alternatively, line 44 could be closed and the hoist controlled by an independent means, and the device could be used to regulate the pumping function of the grout supply. Of course, when the device operates to regulate only one function, it can operate only within the limits ofits own ability and the uncontrolled function must sometimes be limited by other means to avoid running away from the automatic control. Hence, in applying this device to control only one of two simultaneous operations, it should regulate the dominant function or operation.

In the apparatus for producing uncased pressurized cast-in-place concrete foundation piles, the hoist normally functions much faster than the pump, and the real control problem in the production of such piles is to operate the auger hoist only as necessary while the grout supply pump runs constantly at full speed. It will be apparent that the valve 26 in either of these alternatives where only a single variable is controlled will constitute or serve as a modulating valve rather than as a proportioning valve, it being understood that the outlet of valve Cir 26, which is not functioning, will-be plugged or closed. Thus, if valve 26 is to modulate the rate of operation of motor 24 operating the hoist 23, the outlet 32 of the valve 26 will be closed. Similarly, if the valve 26 is employed solely to modulate the rate of operation of the motor 18 of the pump for grout, line 44 and the outlet 30 of the valve 26 will be closed.

While the preferred embodiments of the invention have been illustrated and described, it'will be understood that changes in the construction may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In combination, an earth auger having a hollow stem provided with ,a discharge aperture adjacent its bottom end, power driven means for hoisting said auger, power driven means for supplying grout to said auger stern under pressure, means for discharging compressed air into said stem adjacent said discharge aperture, pressure responsive means for modulating one of said power driven means including .a modulating valve, afirst means connected to said means for discharging air to said stern and operative to actuate said valve in one sense and direction, pneumatic means for actuating said valve in opposite sense and direction, and means including a manually operable valve and operative to supply air under pressure to said last named pneumatic means.

2. In combination, an earth auger having a hollow stem provided with a discharge aperture adjacent its bottom end, power driven auger hoisting means wherein a first sense of operation provides an increase in the rate of hoisting and a second sense provides a decrease in said rate, power driven grout supply means connected to said auger stem for grout supply under pressure wherein a sense of operation opposite said first sense provides a decrease in the rate of grout supply provided by said supply means and a sense opposite said second sense pro- "vides 'an increase in the latter rate, compressed air supply means discharging into said stem adjacent said discharge aperture, fluid pressure actuated means for modulating the operation of said auger hoisting means and of said grout supply means wherein said senses of operation are opposite with respect to each other and including a proportioning valve, a first means connected to said compressed air supply means and operative to actuate said proportioning valve in one sense and direction, a second pneumatic means connected to said air supply means and operative to actuate said proportioning valve in opposite sense and direction to actuation of said valve by said first means, and a manually operable valve in said air supply means for regulating the pressure of air supplied to said second pneumatic means independently of the pressure of air supplied to said first means.

3. The combination defined in claim 2 wherein each of said auger hoisting means and grout supply means is responsive to fluid pressure, means for supplying an operating fluid under pressure to said proportioning valve, and separate delivery means for the operating fluid connecting said proportioned valve respectively to said auger hoisting means and grout supply means to deliver to each of the latter a portion of said operating fluid as determined by the setting of said proportioning valve.

4. Means for controlling the force with which and the location at which concrete grout is discharged from a discharge opening of a tubular stem of an augerin a subterranean cavity to form a cast-in-place pile, comprising an auger having a tubular stem and a discharge opening, auger hoisting means wherein a first sense of operation provides an increase in the rate of hoisting and a second sense provides a decrease in said rate, means for supplying grout to said tubular auger stem under pressure wherein a sense of operation opposite said first sense provides a decrease in the rate of grout supply provided by said supply means and a sense opposite said second senseprovides an increase in the latter rate, means for supplying compressed air into said tubular auger stem adjacent said opening, a modulating controller having a shiftable control element and etfective for simultaneously varying the actuation of said auger hoisting means and grout supply means wherein said senses of operation are opposite with respect to each other, means responsive to the air pressure in said tubular auger stem and tending to actuate said shiftable control element of said modulating controller in one direction, and manually controlled pressure actuated means tending to actuate said shiftable control element of said modulating controller in the opposite direction.

5. A control system comprising a pressure responsive power driven means for feeding concrete grout, a grout discharging tubular stern connected to said driven means and having a discharge port, means for applying compressed air within said stem adjacent the discharge port to sense the resistance of the flow of said grout therefrom, a regulating valve having a shiftable control member, a first air-actuated means connected to said compressed air applying means for urging said valve control member in one direction, a second air-actuated means connected to a source of compressed air for urging said valve control member in opposite direction, manual means for controlling the air pressure applied to said second air-actuated means independently of the pressure applied by said first air-actuated means, means for supplying operating fluid under pressure to said pressure responsive power driven means for feeding grout, said regulating valve being interposed in said last named means to regulate the rate of flow of operating fluid in said last named means to drive said power driven means in feeding grout to said discharge port, movement of said valve control member in one direction increasing the flow of operating fluid to increase the feeding rate of grout by said power driven means and movement of said valve control member in the other direction decreasing said feeding rate of grout by said power driven means, whereby the rate of grout discharged from said stem may be varied as related to said resistance sensed in said stem.

6. A control system for coordinating simultaneous operations, comprising a fluid pressure responsive grout supply means connected to an auger having a tubular stem with a grout discharge outlet,va fluid pressure responsive auger hoisting means independent of said grout supply means, means for sensing a pressure in said stem responsive to the functioning of said grout supply and auger hoisting means when said grout discharge outlet isbelow ground level, said last named means including a fluid pressure line, a coordinating valve having a shiftable control part, a first valve-part positioning means for actuating said shiftable valve part in one direction responsive to the pressure in said fluid pressure line, a second valve-part positioning means for actuating said shiftable valve part in a direction opposite to and simultaneously with actuation of said shiftable valve part by said first valve-part positioning means, manual means for controlling the fluid pressure applied to said second valvepart positioning means independently of the pressure applied to said first valve-part positioning means, means for supplying an operating fluid under pressure to said coordinating valve, and separate operating fluid delivery means connecting said coordinating valve to said respective grout supply means and auger hoisting means, the position of said shiftable valve part proportioning the rate of supply of said operating fluid through said respective delivery means whereby movement of said valve part in one direction increases the rate of hoisting and decreases the rate of grout supply and movement of said valve part in the opposite direction reduces the rate of hoisting and increases the rate of grout supply.

7. A control system as defined in claim 6 wherein said means for supplying an operating fluid is hydraulic and said operating fluid delivery means include hydraulically actuated controls for said grout supply means and auger hoisting means, respectively.

8. A control system as defined in claim 6 wherein said means for supplying an operating fluid is pneumatic and said operating fluid delivery means include pneumatically actuated controls for said grout supply means and auger hoisting means, respectively.

9. A control system as defined in claim 6, and means for indicating the pressure in said fluid pressure line and first valve-part positioning means, and means for indicating the pressure in said secondvalve-part positioning means.

References Cited by the Examiner FOREIGN PATENTS 568,333 l/l933 Germany.

EARL J. WITMER, Primary Examiner.

WILLIAM I. MUSHAKE, Examiner. 

1. IN COMBINATION AN EARTH AUGER HAVING A HOLLOW STEM PROVIDED WITH A DISCHARGE APERTURE ADJACENT ITS BOTTON END, POWER DRIVEN MEANS FOR HOISTING SAID AUGER, POWER DRIVEN MEANS FOR SUPPLYING GROUT TO SAID AUGER STEM UNDER PRESSURE, MEANS FOR DISCHARGING COMPRESSED AIR INTO SAID STEM ADJACENT SAID DICHARGE APERTURE, PRESSURE RESPONSIVE MEANS FOR MODULATING ONE OF SAID POWER DRIVEN MEANS INCLUDING A MODULATING VALVE, A FIRST MEANS CONNECTED TO SAID MEANS FOR DISCHARGING AIR TO SAID STEM 